The Flow Short Scale (FSS) Dimensionality and What MIMIC Shows on Heterogeneity and Invariance

The purpose of this research was to examine the psychometric properties of
the Flow Short Scale by Rheinberg, Vollmeyer, and Engeser in 160 Greek
adults. State flow (as opposed to dispositional flow) was measured while participants were involved in a leisure time activity. First, construct validity was
evaluated with factor analysis techniques like ICM-CFA, ESEM, Bifactor CFA
and Bifactor ESEM. A total of 15 alternative models were evaluated. Two solutions showed optimal fit. First, it was the two-factor structure replicating the
original structure but with different item allocation on each factor, probably
due to cultural differences. Second, it was a shorter version of FSS with 6
items in the two original factors instead of 10. A MIMIC model indicated a
significant direct effect of age on FSS factors thus, population heterogeneity. A
significant direct effect on an indicator was also found, hence measurement
noninvariance. Reliability (α and ω) was acceptable, but not AVE. Flow had a
significant positive, moderately strong relation with emotionality and life satisfaction. In sum, the suggested factor structures for FSS were found to be reliable and valid to use in Greek cultural context.